diagonalMatrix(Ring,ZZ,ZZ,List) -- make a diagonal matrix from a list

• Function: diagonalMatrix

• Usage:

  diagonalMatrix(R,L)

  diagonalMatrix L

  diagonalMatrix(m,n,L)

  diagonalMatrix(R,m,n,L)

• Inputs:
  • R, a ring, the ring of the matrix, if specified
  • m, an integer, the number of rows, if specified
  • n, an integer, the number of columns, if specified
  • L, a list, of elements in the ring R not longer than m or n
• Outputs:
  • a matrix, a diagonal matrix whose diagonal entries are the elements of L

i1 : R = QQ[a..d];

i2 : diagonalMatrix{a,b,c,3/4}

o2 = | a 0 0 0   |
     | 0 b 0 0   |
     | 0 0 c 0   |
     | 0 0 0 3/4 |

             4      4
o2 : Matrix R  <-- R

i3 : diagonalMatrix(3,5,{a,b,3/4})

o3 = | a 0 0   0 0 |
     | 0 b 0   0 0 |
     | 0 0 3/4 0 0 |

             3      5
o3 : Matrix R  <-- R

i4 : diagonalMatrix(R,{1,2,3})

o4 = | 1 0 0 |
     | 0 2 0 |
     | 0 0 3 |

             3      3
o4 : Matrix R  <-- R